Trimmings are portions of meat which are remaining after deboning the carcase and preparing the primal cuts, so microbiological markers must be controlled and are used as a trade standards. There are specifications of microbiological markers for mechanically recovered meat and ground meat which require absence of pathogenic strains. Among pathogens Listeria monocytogenesand E. coliO157:H7 need to be seriously taken into account. There are several types of E. coli strains that may cause gastrointestinal illness in humans. Verotoxin-producing or Shiga-toxin producing E. coli(VTEC or STEC) have emerged as important food-borne pathogens. Cattle is a reservoir of zoonotic STEC which are transmitted to humans through meat and meat products (Caprioli et al. 2005). Listeria monocytogenesusually cause seriously affected cases and even deaths. In 2010, 1601 confirmed cases of listeriosis were reported in Europe, 17% of which ended fatally (EFSA, 2012).